<template>
    <div>
        <div style="margin: 10px 0">
            <el-input style="width: 200px" placeholder="请输入名称" suffix-icon="el-icon-search" v-model="name"></el-input>
            <el-button class="ml-5" type="primary" @click="load">搜索</el-button>
            <el-button type="info" @click="reset">重置</el-button>
        </div>
        <div style="margin: 10px 0">
            <el-button type="primary" @click="showUploadDialog" class="ml-5">点击上传 <i class="el-icon-top"></i>
            </el-button>
            <el-popconfirm
                    class="ml-5"
                    confirm-button-text='确定'
                    cancel-button-text='我再想想'
                    icon="el-icon-info"
                    icon-color="red"
                    title="您确定批量删除这些数据吗？"
                    @confirm="delBatch"
            >
                <el-button type="danger" slot="reference">批量删除 <i class="el-icon-remove-outline"></i></el-button>
            </el-popconfirm>
        </div>
        <el-table :data="tableData" border stripe
                  @selection-change="handleSelectionChange" :header-cell-style="{background:'#eee',color:'#000000'}">

            <el-table-column type="selection" width="55"></el-table-column>
            <el-table-column prop="id" label="ID" width="80"></el-table-column>
            <el-table-column prop="fileName" width="250" label="文件名称"></el-table-column>
            <el-table-column prop="fileType" label="文件类型">
                <template slot-scope="scope">
                    {{ scope.row.fileName | transformType }}
                </template>
            </el-table-column>
            <el-table-column prop="fileSize" label="文件大小(mb)">
                <template slot-scope="scope">
                    {{ scope.row.fileSize | transformByte }}
                </template>
            </el-table-column>
            <el-table-column label="预览">
                <template slot-scope="scope">
                    <el-button type="primary" @click="lookonline(scope.row.url)">预览</el-button>
                </template>
            </el-table-column>
            <el-table-column label="下载">
                <template slot-scope="scope">
                    <el-button type="primary" @click="download(scope.row.url,scope.row.fileType)">下载</el-button>
                </template>
            </el-table-column>
            <el-table-column width="80" label="启用">
                <template slot-scope="scope">
                    <el-switch v-model="scope.row.enable" active-color="#13ce66" inactive-color="#ccc"
                               @change="changeEnable(scope.row)"></el-switch>
                </template>
            </el-table-column>
            <el-table-column label="操作" width="200" align="center">
                <template slot-scope="scope">
                    <el-popconfirm
                            class="ml-5"
                            confirm-button-text='确定'
                            cancel-button-text='我再想想'
                            icon="el-icon-info"
                            icon-color="red"
                            title="您确定删除吗？"
                            @confirm="del(scope.row)"
                    >
                        <el-button type="danger" slot="reference">删除 <i class="el-icon-remove-outline"></i></el-button>
                    </el-popconfirm>
                </template>
            </el-table-column>
        </el-table>
        <div style="padding: 10px 0">
            <el-pagination
                    @size-change="handleSizeChange"
                    @current-change="handleCurrentChange"
                    :current-page="pageNum"
                    :page-sizes="[2, 5, 10, 20]"
                    :page-size="pageSize"
                    layout="total, sizes, prev, pager, next, jumper"
                    :total="total">
            </el-pagination>
        </div>
        <FileUpload :fileTableVisible="fileTableVisible" @uploadFileList="uploadFileList"
                    @changeFileDialogVisible="changeFileDialogVisible"></FileUpload>
    </div>
</template>

<script>
    import FileUpload from "@/components/FileUpload";
    import axios from 'axios'
    import streamSaver from "streamsaver"

    export default {
        name: "File",
        components: {FileUpload},
        data() {
            return {
                fileTableVisible: false,
                uploadHeaders: localStorage.getItem("token") ? JSON.parse(localStorage.getItem("token")) : '',
                tableData: [],
                name: '',
                multipleSelection: [],
                pageNum: 1,
                pageSize: 10,
                total: 0,
                headers: localStorage.getItem('token'),
            }
        },
        created() {
            this.load()
        },
        methods: {
            showUploadDialog() {
                //如果有文件没有上传成功就保留这个文件，这样下次打开弹框还有记录
                this.fileTableVisible = true
            },
            changeFileDialogVisible(value) {
                this.fileTableVisible = value
            },
            uploadFileList() {
                this.load()
            },
            async httpRequest(file, callback) {
                let progress = 0
                const formData = new FormData()
                formData.append('file', file.raw) // 将文件添加到FormData对象中
                axios({
                    headers: {'Content-Type': 'multipart/form-data', 'token': this.uploadHeaders},
                    method: 'post',
                    url: 'http://localhost:9090/file/upload',
                    data: formData,
                    onUploadProgress: progressEvent => { // 获取文件上传进度 axios自带的
                        progress = (progressEvent.loaded / progressEvent.total * 100) | 0
                        callback({progress, status: 'uploading'})
                    }
                }).then(() => { // 成功状态
                    callback({progress, status: 'success'})
                }).catch(() => { // 失败状态
                    callback({progress, status: 'error'})
                })
            },
            load() {
                this.request.get("/file/page", {
                    params: {
                        pageNum: this.pageNum,
                        pageSize: this.pageSize,
                        name: this.name,
                    }
                }).then(res => {
                    this.tableData = res.data.records
                    this.total = res.data.total
                })
            },
            changeEnable(row) {
                this.request.post("/file/update", row).then(res => {
                    if (res.code === 200) {
                        this.$message.success("操作成功")
                    }
                })
            },
            del(file) {
                console.log(file)
                this.request.post("/file/", file).then(res => {
                    if (res.code === 200) {
                        this.$message.success("删除成功")
                        this.load()
                    } else {
                        this.$message.error("删除失败")
                    }
                })
            },
            handleSelectionChange(val) {
                console.log(val)
                this.multipleSelection = val
            },
            delBatch() {
                // let ids = this.multipleSelection.map(v => v.id)  // [{}, {}, {}] => [1,2,3]
                if (this.multipleSelection.length === 0) {
                    this.$message.warning("请选择删除的文件")
                    return
                }
                this.request.post("/file/del/batch", this.multipleSelection).then(res => {
                    if (res.code === 200) {
                        this.$message.success("批量删除成功")
                        this.load()
                    } else {
                        this.$message.error("批量删除失败")
                    }
                })
            },
            reset() {
                this.name = ""
                this.load()
            },
            handleSizeChange(pageSize) {
                console.log(pageSize)
                this.pageSize = pageSize
                this.load()
            },
            handleCurrentChange(pageNum) {
                console.log(pageNum)
                this.pageNum = pageNum
                this.load()
            },

            // 下载文件
            download(url) {
                const filename = url.substring(url.lastIndexOf('/') + 1)
                // 创建一个可写流
                var fileStream = streamSaver.createWriteStream(filename);
                // 下载文件
                fetch(url).then((response) => {
                    // 获取响应流
                    var reader = response.body.getReader();
                    // 创建可读流
                    var stream = new ReadableStream({
                        start: function (controller) {
                            // 读取响应流
                            return pump();

                            function pump() {
                                return reader.read().then((result) => {
                                    // 如果已经读取完毕，则关闭流
                                    if (result.done) {
                                        controller.close();
                                        return;
                                    }
                                    // 发送数据块
                                    controller.enqueue(result.value);
                                    // 更新下载进度
                                    // this.progress = Math.round((fileStream.bytesWritten / response.headers.get('Content-Length')) * 100);
                                    // 继续读取
                                    return pump();
                                });
                            }
                        }
                    });
                    // 将可读流写入可写流
                    stream.pipeTo(fileStream);
                });
            },
            lookonline(url) {
                console.log(url)
                window.open('http://127.0.0.1:8012/onlinePreview?url=' + encodeURIComponent(Base64.encode(url)));
            }
        },
        filters: {
            transformByte(size) {
                if (!size) {
                    return '0B'
                }
                const unitSize = 1024
                if (size < unitSize) {
                    return size + ' B'
                }
                // KB
                if (size < Math.pow(unitSize, 2)) {
                    return (size / unitSize).toFixed(2) + ' K';
                }
                // MB
                if (size < Math.pow(unitSize, 3)) {
                    return (size / Math.pow(unitSize, 2)).toFixed(2) + ' MB'
                }
                // GB
                if (size < Math.pow(unitSize, 4)) {
                    return (size / Math.pow(unitSize, 3)).toFixed(2) + ' GB';
                }
                // TB
                return (size / Math.pow(unitSize, 4)).toFixed(2) + ' TB';
            },
            transformType(filename) {
                return filename.substr(filename.lastIndexOf('.') + 1)
            }
        }
    }
</script>

<style scoped>

</style>
